/* eslint-disable */
(function(){
    let minSampleRate = 22050
    self.onmessage = function(e) {
      transcode.transToAudioData(e.data)
    }
    var transcode = {
      transToAudioData: function(audioDataStr, fromRate = 16000, toRate = 22505) {
        let outputS16 = transcode.base64ToS16(audioDataStr)
        let output = transcode.transS16ToF32(outputS16)
        output = transcode.transSamplingRate(output, fromRate, toRate)
        output = Array.from(output)
        self.postMessage({
          data: output,
          rawAudioData: Array.from(outputS16)
        })
      },
      transSamplingRate: function(data, fromRate = 44100, toRate = 16000) {
        var fitCount = Math.round(data.length * (toRate / fromRate))
        var newData = new Float32Array(fitCount)
        var springFactor = (data.length - 1) / (fitCount - 1)
        newData[0] = data[0]
        for (let i = 1; i < fitCount - 1; i++) {
          var tmp = i * springFactor
          var before = Math.floor(tmp).toFixed()
          var after = Math.ceil(tmp).toFixed()
          var atPoint = tmp - before
          newData[i] = data[before] + (data[after] - data[before]) * atPoint
        }
        newData[fitCount - 1] = data[data.length - 1]
        return newData
      },
      transS16ToF32: function(input) {
        var tmpData = []
        for (let i = 0; i < input.length; i++) {
          var d = input[i] < 0 ? input[i] / 0x8000 : input[i] / 0x7fff
          tmpData.push(d)
        }
        return new Float32Array(tmpData)
      },
      base64ToS16: function(base64AudioData) {
        base64AudioData = atob(base64AudioData)
        const outputArray = new Uint8Array(base64AudioData.length)
        for (let i = 0; i < base64AudioData.length; ++i) {
          outputArray[i] = base64AudioData.charCodeAt(i)
        }
        return new Int16Array(new DataView(outputArray.buffer).buffer)
      },
    }
  })()
  